What would the country's reaction have been, seventy years ago, if somebody had shot up a recruiting center -- or anyplace else -- as an action in solidarity with the Third Reich or the Empire of Japan? What would the reaction be if an actual soldier in one of those armies had done so on our soil?
It would at least have been seen as an act of war or treason or something. The country would be stirred with anger, and the President would be voicing his resolve to fight back, to punish those responsible. Instead, we get a ho-hum, nothing to see here response from our leaders and the media and a lot of RIP memes on Facebook.
I'd also bet that the military, seventy years ago, even here in the US, would be armed and ready, at least with MPs standing guard at every target of opportunity and officers toting sidearms while on duty.